PIP (Property Information Portal) architecture

Project goal

The Property Information Portal (PIP) is the public lookup for a property on the tax map of the City of New York, published by the Department of Finance. Its purpose is that anyone looking up a lot — an owner, a professional, or staff of the department itself — can see, on one screen, that property’s tax identity, its physical description, its assessment, its exemptions, the register documents, the tax map history, and its position on the map. Today each of those pieces lives in a different system; the portal brings them together so nobody has to open each system separately.

That assembly has one shared key: the BBL (Borough-Block-Lot), a ten-character identifier made of the borough (1 digit), the block (5), and the lot (4). Almost every query in the portal filters on that value, or on a field derived from it (PARID, CONDO_BILLING_BBL, UNIT_BBL, PARENT_BBL, AIR_LOT_BBL, SUB_LOT_BBL).

The source systems the portal reads, and which it does not replace, are these:

The goal is met when the application does these four things, in this order.

1. Locate the property with the key the user brings. The Find a Property panel accepts borough, block, and lot; an address; the condominium number; the REUC identifier; the air or subterranean lot number; a click on the map; or an external link that already carries borough, block, and lot separately. An address is turned into a point and intersected with the parcel layer. If the point falls inside no parcel, the search is repeated over a 100-foot area around it.
2. Classify that BBL. The same ten-digit number can be a condominium unit, a condominium billing BBL, an air lot, a subterranean lot, a current parcel, a dropped lot, or a dropped condominium. The search queries those layers in that order and stops at the first one that returns records. The resulting type (unit, condo, air, sub, parcel, dropParcel, or dropCondo) decides which parcel is highlighted on the map and which extra cards the detail panel shows. A unit, for example, is drawn on the condominium base parcel (CONDO_BASE_BBL); an air or subterranean lot is drawn on its parent parcel (PARENT_BBL).
3. Compose the detail panel and place it on the map. Once the BBL is classified, the browser queries the ArcGIS Online feature services in parallel (organization yG5s3afENB5iO9fj, portal https://nyc.maps.arcgis.com) and the ACRIS documents. The result is split across cards: property data, building, land, condominium and unit when they apply, REUC, assessment, exemptions, sales, mortgages, tax map history, and neighborhood. The 2D map frames and highlights the parcel. In 3D it leaves visible only the unit, air, subsurface, and building volumes that belong to that BBL. A block, with no lot, opens a shorter view: only the tax map history for that block.
4. Leave any data change in the source systems. The portal reads; it does not write to the geodatabase and it does not calculate the tax. Paying, opening the property tax account, filing a tax map action, or reviewing exemptions and assessments are links to Department of Finance sites (*.nyc.gov). Those links carry the BBL as the account identifier (pin).

Technically, PIP is a static site written in React, TypeScript, and Vite. It has no business server of its own: every query leaves the browser for ArcGIS Online, for the ACRIS proxy (propertyinformationportal.nyc.gov), and for the Cyclomedia imagery API. The feature services that feed the detail panel respond without a sign-in. IIS publishes the site and rewrites the single-page application routes so that an address such as /parcels/parcel/1001230045 opens the detail panel even though the server has no such folder.

For anyone maintaining the code, that goal is also the test of a change. A modification fits the portal if it still lets someone locate a lot, classify it, compose its detail panel, and show it on the map. The rest of this documentation describes how that path is built, so the effect of a change can be judged before it is made.

How this is organized

The annexes in generated/ hold the inventory: routes, components, and services. The interactive diagrams are in diagrams/, and index.html gathers everything into one page that can be opened offline.

Glossary

Scope

Out of scope:

• The published schema of each feature service (fields, domains, and permissions). The tables in this document list the layers the code queries, not the full service contract.
• Cyclomedia credentials and package-registry keys. They live in configuration and are not reproduced here.
• The contents of the portal web maps and the quality dashboard (/qa), which live outside this repository.

Change history

Diagrams

1. Overview

In short: the platform has four layers. The user works in a single-page web application; that application draws an ArcGIS web map; the detail-panel data is read from ArcGIS Online feature services; and several external systems (ACRIS, Cyclomedia, and the Department of Finance pages) complete the lookup without a business server of their own. The data layer is the city’s cadastral record: it follows the national spatial-data conventions for property information, and the portal only reads it.

Diagram: System architecture

The four layers

Data

PIP’s data layer is the city’s piece of a Spatial Data Infrastructure (SDI) for property and cadastral information. In the United States that infrastructure is coordinated nationally as the National Spatial Data Infrastructure (NSDI). The NSDI connects policy, technology, and standards so that counties and cities can exchange parcel and infrastructure data without each government inventing its own model.

The Department of Finance publishes the Digital Tax Map and the property views that the portal reads. Those layers are the authoritative local record. The portal does not replace that record; it queries it. The four pieces below are the conventions that record follows, and that the feature services therefore expose. The catalog of those services is in 5. Data and services.

National and local governance

The Federal Geographic Data Committee (FGDC) sets the NSDI framework. Local governments — counties in most of the country, and the city itself in New York — remain the source of cadastral truth. They decide how a lot is identified, when a parcel is created or dropped, and which assessment and exemption views sit beside the map.

In this portal that governance shows up as a single key, the BBL, and as a set of published feature services on ArcGIS Online. Changing a lot, an assessment, or a register document happens in those source systems, not in the application.

Property and cadastral standards

Parcel and real-property information is described under two FGDC technical standards:

The BBL is the city’s implementation of that cadastral identifier: borough, block, and lot, padded to ten characters. Derived fields (CONDO_BILLING_BBL, UNIT_BBL, PARENT_BBL, AIR_LOT_BBL, SUB_LOT_BBL) keep the special lots inside the same standard.

Associated public infrastructure standards

Local governments do not only map private property. They also map the services that meet that property in the public right-of-way: addresses, streets, and utilities.

In the portal that associated infrastructure is the REUC (appurtenant utility) record, the street-level imagery at the parcel, and the neighborhood districts from MapPLUTO. None of those replace the cadastral lot; they hang off it.

Interoperability and commercial platforms

Day-to-day cadastral management in the United States sits with the local government. Those offices typically run commercial GIS that already implements FGDC content, Open Geospatial Consortium (OGC) service interfaces, and ISO/TC 211 geographic-information models.

PIP is built on that stack. The maps and the detail-panel data are ArcGIS Online web maps and feature services. The browser reads them with the ArcGIS Maps SDK — query over REST — and never writes back.

Path of a lookup

The example below follows what happens when the user searches for a lot by borough, block, and lot. Every other search ends on the same detail panel.

1. Form. SearchBBL builds the ten-digit BBL and looks it up, in this order, as a condominium unit, a condominium, an air lot, a subterranean lot, a map parcel, a dropped lot, and a dropped condominium.
2. Navigation. If there is a result, the application opens /parcels/<type>/<bbl>. The type (unit, condo, air, sub, parcel, dropParcel, or dropCondo) decides which extra card is shown.
3. Map. AppContext highlights the parcel on the map and, in 3D, filters the unit, air, and subsurface layers by the parent BBL.
4. Detail panel. useDetails queries, in parallel, the detail layers, the assessment, the exemptions, the tax map history, and, through the portal proxy, the ACRIS documents.
5. Presentation. DetailsPanelBBL splits that response across the cards of the detail panel.

Diagram: Sequence of a BBL lookup

Technology

Design principles

• Everything is organized by BBL. The detail panel, the map highlight, and the 3D layers filter on that identifier or on a derived field (PARID, CONDO_BILLING_BBL, PARENT_BBL, UNIT_BBL).
• Configuration lives in one module. Map and service addresses are in AppConfig.ts. Changing environment means changing those URLs.
• The map and the panel share state. AppContext holds the view, the selected parcel, and the 3D layers. Panels do not talk to each other: they navigate and read that context.
• The application only reads. There are no geoprocessing jobs and no writes to the geodatabase. Actions that change data (pay, file a request, open the property tax account) are links to Department of Finance sites.

2. Application

In short: PIP is a single page with three zones: header, side panel, and map. The route decides which panel is shown. Below 768 px the panel and the map take turns; on desktop they sit side by side and the panel can be hidden. Map state lives in AppContext.

Annexes: routes · components

Layout

App.tsx chooses the layout from the window width:

The routes /cyclomedia/:x/:y/ and /qa/ show neither header nor map: they fill the window with the street viewer or the quality dashboard.

The header (Header.tsx) carries the Department of Finance logo, the title Property Information Portal, and external links: tax map filings, exemptions and assessments, the user guide (/pdf/PIP_UserGuide.pdf), and the Map Tool experience.

Routes

Defined in AppRoutes.ts and mounted in App.tsx.

AppRoutes also declares /reuc/:boro/:reucNumber and /history/:type/:bbl. Those routes are not mounted in App.tsx. The REUC search navigates to /reuc/…, so today it does not open a panel.

Shared state

AppContext is the only global UI state. It stores:

Operations the context exposes:

• updateSelectedParcel / updateSelectedParcelByBBL. Highlight the parcel and frame the map. In 3D they apply a definitionExpression to the volume layers so only what belongs to that BBL is drawn; if nothing is selected, the expression is 1=2 (nothing is drawn).
• updateBlockHighLight. Finds the block (BORO and BLOCK) and highlights it.
• multipleHighlight. Highlights a list of BBLs. The detail panel uses it when a condominium groups several parcels.
• changeSelectedAreaByBBL. Locates a 3D volume by its BBL field.

Startup is in main.tsx: BrowserRouter, AppContextProvider, and App. The accounts provider (AccountsContext) and the AppSecured variant exist in the repository, but they are not mounted.

Web maps

Map.tsx loads the 2D map first and offers a control to switch to the 3D scene. The identifiers are in AppConfig:

A click on the map queries the parcel layer at the point. If there is a BBL different from the current one, it navigates to /parcels/parcel/<bbl>. Otherwise it runs a hit test and, if it hits a 3D volume, selects it with changeSelectedAreaByGraphic.

The initial extent and the fallback basemap are in ArcGIS.ts (Web Mercator, basemap topo-vector). As soon as the web map is ready, its own extent and layers take over.

Authentication

AppConfig.auth points at the portal https://nyc.maps.arcgis.com and stores the registered application identifier. useAccountManager implements sign-in with ArcGIS REST JS. Because main.tsx does not mount that flow, queries to the feature services go out without a user token. The services the detail panel uses respond anonymously.

3. Components

In short: the interface is split into a shell (header, panel, map), a search panel with seven modes, the lot detail panel, and two history views. Almost all detail-panel data passes through the useDetails hook. Paths in this document are relative to src/.

Annex: component inventory

Shell

Header — Header

• Role: Department of Finance branding and menus of external links. It does not query data.
• Where: every route except Cyclomedia and the quality dashboard.
• File: components/Header/Header.tsx.

Panel — Side frame

• Role: title, back button, and the slot where search or the detail panel is mounted.
• File: components/Panel/Panel.tsx.

Map — Map

• Role: creates the 2D or 3D view, registers the click, and switches web map.
• Depends on: hooks/useWebMap.ts, context/MapController.ts.
• File: components/Map/Map.tsx.

Cyclomedia — Street imagery

• Role: opens a Street Smart panorama at the coordinates that arrive on the route. The spatial reference is EPSG:26918. A 2D variant (Cyclomedia2D.tsx) requests a rendered image from the Atlas API.
• Where: route /cyclomedia/:x/:y/, opened from the detail-panel header. The detail panel projects the parcel centroid into that projection before navigating.
• File: components/Cyclomedia/Cyclomedia.tsx.

DisclaimerPopup — Notice

• Role: a terms notice, remembered in a disclaimerAccepted cookie. In the desktop layout of App.tsx the call is commented out, so it is not shown.

Search

SearchPanel titles the side panel Find a Property and offers seven modes. Each mode is a form built with React Hook Form and Yup. The address widget is the ArcGIS SDK Search, limited to six results.

The panel also links to the Department of Finance property tax account (Open Property Tax Account).

Lot detail panel

DetailsPanelBBL reads :type and :bbl from the route, locates the parent parcel when the type is not the parcel itself, and calls useDetails.

The detail-panel header (HeaderCard) shows the address, the BBL, and a card index. From there the user prints the panel (a new window with the panel contents), opens Cyclomedia, and, if the lot is a condominium, picks the unit.

TaxCard and LibraryCard exist as components. TaxCard is not mounted in the panel: it groups links to the property tax account (balance, bill, benefits, assessment). Those links use the BBL as pin.

Block and history

DetailsPanelBlock

• Role: a reduced record for a block. It shows only tax map history (library, change book, and historical books).
• Data: hooks/useDetailsBlock.tsx, the same three layers as the history card on the detail panel, filtered by borough and block.
• File: components/panels/DetailsPanelBlock/DetailsPanelBlock.tsx.

History

• Role: a desktop screen for looking up history by typing borough and block, without going through the detail panel.
• Route: /searchHistory.
• File: components/History/History.tsx.

RedirectPanel

• Role: turns a URL /parcels/<borough>/<block>/<lot> into the ten-digit BBL and applies the same classification order as SearchBBL.
• File: components/panels/RedirectPanel/RedirectPanel.tsx.

Data loading

useDetails is the only place that assembles the detail panel. queryMain(bbl) fires these reads as a sequence of functions, and in parallel inside each function:

The panel also calls queryNeighborhoodDetails, queryCondoDetails, queryBuildingDetails, and queryPropertyTypes in addition to queryMain, for the neighborhood, the condominium record, and the list of air, subterranean, and condominium lots associated with the parcel.

4. Lookup flow

In short: every lookup ends on one of two screens. If the user brings a lot, the application classifies the BBL and opens the detail panel. If the user brings a block, it opens only the tax map history. The map follows both: it highlights the parcel or the block.

Diagrams: Property search · Sequence of a BBL lookup

Classifying a BBL

SearchBBL and RedirectPanel use the same order. They stop at the first service that returns records.

If none of them respond, the form shows BBL was not found. The external link /parcels/<borough>/<block>/<lot> pads the block to five digits and the lot to four before it enters this list.

The BBL is built like this: one borough digit, the block padded with leading zeros to five characters, and the lot padded to four. Borough 1, block 16, and lot 1 produce 1000160001.

Other search modes

What the detail panel does when it opens

1. It compares :type and :bbl on the route with the last values already loaded. If they have not changed, it does not query again.
2. Depending on the type, it obtains the parent parcel (see the table in 3. Components) and calls updateSelectedParcelByBBL.
3. It calls queryMain with the detail-panel BBL (the unit’s BBL, if the type is unit).
4. It requests the neighborhood, the associated property types, and, for condominiums, the unit list (CONDO_BASE_BBL_KEY, excluding rows with CINC_PARENT).
5. It projects the parcel geometry to EPSG:26918 so Cyclomedia can be opened.
6. It removes the loading indicator. Each card paints the part of state that belongs to it; if a query has not returned yet, that card stays empty.

Pressing Find Another Property clears the selected parcel and returns to /.

Volumes in 3D

When the map is in 3D and a parcel is selected, AppContext.updateSelectedCondo3D walks the layers from useAreas and leaves visible only what satisfies bblBaseField = BBL of the parcel. Those layers are:

Choosing a unit on the detail panel also calls changeSelectedAreaByBBL(AreaType.unit, bbl), which queries the 3D feature service and highlights that volume.

Print and links

• Print. HeaderCard opens a window with the panel HTML and calls window.print().
• Property tax account. Several cards and the search panel link to a836-pts-access.nyc.gov with the BBL as pin and jur=65.
• Guide. The header opens /pdf/PIP_UserGuide.pdf, a static file that IIS does not rewrite (see 6. Build and deployment).

5. Data and services

In short: the application has no database of its own. It reads feature services and scene services from ArcGIS Online, and register documents through the portal proxy. The key of almost every query is the ten-character BBL, using the field name each layer expects.

Annex: service catalog

Diagram: Sequence of a BBL lookup

The BBL key

A BBL is a ten-character string: borough (1) + block (5) + lot (4), with leading zeros. Layers do not always use the same field name:

For a block, history queries split the BBL: the first character is the borough and the next five, with leading zeros removed, are the block. MapPLUTO filters on BoroCode and Block the same way.

Daily tax map service

Most of the detail panel comes from DTM_ETL_DAILY_view (https://services6.arcgis.com/yG5s3afENB5iO9fj/arcgis/rest/services/DTM_ETL_DAILY_view/FeatureServer).

Other ArcGIS Online services

The three scene services are at https://tiles.arcgis.com/tiles/yG5s3afENB5iO9fj/. DTM_3D_view is on services6, like the rest of the feature services.

The web maps are not queried by a standalone layer URL for the parcel and the block: MapController finds them by the layerId configured inside the map item. If the web map is republished and those identifiers change, highlighting stops finding the layer even though the feature service is unchanged.

ACRIS

Sales and other documents are not in the feature service. useDetails.queryMoreDetails requests two URLs from the portal’s own proxy:

https://propertyinformationportal.nyc.gov/proxy/proxy.ashx?https://a836-acrissds.nyc.gov/AcrisDtm/AcrisDtmApi/AcrisDocuments?returntype=SALES&borough=…&block=…&lot=…

The second call uses returntype=OTHER. Borough, block, and lot come from the daily record or, if they are missing, from the attributes of the selected parcel. The code still has the propertyinformationportal-stg.nyc.gov variant commented out; the active URL is production.

Who reads each group

Links that are not detail-panel data

These destinations open in another tab. They do not return data to the application:

6. Build and deployment

In short: the application is compiled to a static site with Vite. On the server, IIS serves those files and rewrites any route that is not a real file back to the React entry, so the browser router can open a detail panel directly.

Build

index.html also loads, from a CDN, React 18.2, React DOM, Lodash, and the Cyclomedia Street Smart API, plus the Google Analytics tag.

IIS

web.config does three things:

1. HTTPS. Redirects any HTTP request to HTTPS.
2. React routes. If the URL is neither a file nor a directory, and it does not start with /api, /pdf/, or /proxy/, it is rewritten to /. That is how /parcels/parcel/1000160001 reaches the application and React Router resolves the detail panel.
3. Headers. Removes X-Powered-By and Server, and adds X-Frame-Options: SAMEORIGIN, Referrer-Policy: no-referrer, and Access-Control-Allow-Origin: *. A commented content-security policy lists the ArcGIS, Cyclomedia, and CDN origins.

.htaccess repeats the rewrite idea for Apache: anything that is not a file is sent to index.html.

The user guide has to stay under /pdf/, because that path is excluded from the rewrite. The ACRIS proxy lives at /proxy/ on the same site; the application calls propertyinformationportal.nyc.gov/proxy/proxy.ashx, not a relative path.

Build pipeline

azure-pipelines.yml triggers on the feature/develop branch, on an Ubuntu agent:

1. Installs Node.js 18.
2. Configures the Font Awesome registry (the pro icons are not on the public registry).
3. Runs npm install and npm run build.

The pipeline file describes packaging as ArcGIS Pro tasks for the DTM workflows. The step that actually runs is the front-end build. The output comment (dtm_pro_tasks_yyyymmdd.zip) does not match an artifact declared in the visible steps.

Environments

Two environment footprints coexist in the code, with no single switch:

The feature services point at a single ArcGIS Online organization. There is no per-environment copy of the configuration inside AppConfig.

7. Using the portal

In short: the public site opens on a search panel and a tax map. A borough, block, and lot are enough to open the detail panel, highlight the lot, and, for a condominium unit, switch into the 3D scene. The screenshots below are frames from a recording of propertyinformationportal.nyc.gov made on 11 August 2025. The example is Manhattan block 1010, lot 1816.

The screen

The page has three zones. The header carries the Department of Finance mark and the links that leave the portal: tax map filings, exemptions and abatements, valuation, the user guide, and Map Tool. The left panel is the search or the detail panel. The rest of the window is the map, with a 3D control that switches to the scene.

Search by borough, block, and lot

Select chooses the search mode. This recording uses Borough / Block / Lot. Borough is a list (here, Manhattan), and block and lot are typed. Search classifies the ten-digit BBL and opens the detail panel.

Manhattan, block 1010, and lot 1816 become BBL 1010101816. The portal resolves that number as a condominium unit and navigates to /parcels/unit/1010101816.

The detail panel

The panel title changes to Property Details. The header of the panel shows the address (111 West 57th Street, unit PH20), the borough, the block, and the lot, plus shortcuts to the property tax account, print, pay online, and the other Department of Finance actions. A photograph of the front sits beside those shortcuts. The blue chips jump to a card: Property Info, Building, Land, Assessments, Exemptions, Sales, Mortgages, Tax Map History, and Neighborhood.

On the map the condominium’s base lot is filled in cyan and the view zooms to the block. The label on that lot in this recording is C2985, the condominium number. Find Another Property returns to the search panel.

Two controls under the address are specific to a condominium. Condominium switches the record between the unit and the condominium. The unit list on the right names the current unit and its tax lot.

Street-level view

From the detail panel the portal opens the street imagery in its own browser tab, at /cyclomedia/<x>/<y>/. The viewer is a Cyclomedia panorama at the parcel. In this recording the capture date shown in the viewer is 4 April 2025, on West 57th Street beside Central Park Mews. The original detail panel stays open in the other tab.

Cards on the panel

Scrolling the panel (or using the chips) walks the same record. Four cards from this lookup:

The condominium unit card includes the floor plan of the unit, with Previous and Next when there is more than one sheet.

Land shows frontage, depth, area, and zoning. Assessment shows the current market value and taxable assessed value, and a year-by-year table under Assessed Value History. Request for Review and Request AHHS leave the portal for the Department of Finance filing pages.

Mortgages lists recorded documents that are not sales (the sales card is the one before it). The note on the card says the panel shows the recent records and links to ACRIS for the full set.

Tax Map History lists the library dates for the block. Neighborhood shows the community district, council district, land use, and the school and health districts, with links out to CityMaps and ZoLa.

Choosing another unit

On a condominium, the unit control opens a list. Each row is a unit id and its tax lot. Picking one loads that unit’s detail panel and changes the route. In the recording, unit 2 is lot 1802 (/parcels/unit/1010101802) and unit 11A is lot 1803. The map stays on the same condominium lot; the panel and, in 3D, the highlighted volume follow the unit.

The 3D scene

3D replaces the tax map with the scene. The same detail panel stays on the left. Condo units are drawn as translucent volumes stacked on the lot; the selected unit is outlined in green. The control in the corner of the map flips back to 2D.

The layer control on the right lists what the scene is drawing. In this recording the entries are 3D Footprint Selected Building and 3D Footprint All Buildings. The eye beside each row turns that layer on or off.

The blue tab collapses the detail panel so the scene uses the full width. Orbit and zoom move around the stack of units. The selected unit stays outlined. Expanding the tab brings the panel back.

Components

Updated 29/09/2026.

Paths relative to src/.

Detail-panel cards, in components/panels/DetailsPanelBBL/Cards/:

Routes

Updated 29/09/2026.

Types accepted by /parcels/:type/:bbl: unit, condo, air, sub, parcel, dropParcel, dropCondo. The reuc type is commented out in DetailsPanelBBL.

Services

Updated 29/09/2026.

ArcGIS Online organization: yG5s3afENB5iO9fj. Feature services at https://services6.arcgis.com/yG5s3afENB5iO9fj/. Scene services at https://tiles.arcgis.com/tiles/yG5s3afENB5iO9fj/.

Web maps

Portal: https://nyc.maps.arcgis.com.

DTM_ETL_DAILY_view

Other services

Outside ArcGIS